Transition densities and form factors in the triangular α-cluster model of 12C with application to 12C+α scattering.

Densities and transition densities are computed in an equilateral triangular α-cluster model for 12C, in which each α particle is taken as a Gaussian density distribution. The ground state, the symmetric vibration (Hoyle state), and the asymmetric bend vibration are analyzed in a molecular approach and dissected into their components in a series of harmonic functions, revealing their intrinsic structures. The transition densities in the laboratory frame are then used to construct form factors and to compute distorted-wave Born approximation inelastic cross sections for the 12C(α,α') reaction. The comparison with experimental data indicates that the simple geometrical model with rotations and vibrations gives a reliable description of reactions where α-cluster degrees of freedom are involved. [ABSTRACT FROM AUTHOR]